Spun cellulose and viscose products



Patented Oct. 22, 1929 UNITED STATES PATENT OFFICE.

ROBERT e. CAMPBELL; on NEW YORK ILLS NEW YORK SPUN GELLULOSE AND VISCOSE PRODUCTS M o Drawing.

This invention relates, primarily, to spun cellulose and viscose products; it has more especial reference to a filament, element or yarn adapted for textile purposes; and it essentially involve such an element or filament viscose filaments are now extensively utilized in the textile art for making fabrics, etc. Because of certain recognized commercial objections to and inherent defects in these filaments, their use has, to a certain extent and for that reason, been somewhat limited. For

instance, the cellulose filament, when subjected to wetting, loses considerable of its tensile strength and, as a result, fabric manufactured therefrom has proved more or less unsatisfactory. In other words, its wetstrength is materially less than its drystrength. Much experimentation has, as a hill result, been conducted in an attempt to cure this serious defect; but, so far as I am aware, no successful treatment has, before my invention, been proposed. To compensate for the inherent weakness of the element, it has been rather common; practice to combine therewith in knit-ting or weaving other materials, such as silk, wool, etc. Another objection to rayon and similar products is that it is quite harsh to the feel and, for that reason, does not always favorably compare with genuine silk when knit or woven into fabric for certain types of wearing apparel. Still another objection to this product is its relative unworkability in certain machines, requiring certain incidental treatment to adapt it therefor.

It is the object of the present invention to provide a product which has none of these objections. In other words, I have developed a cellulose-element which possesses a satisfactory degree of strength and durability, even after being wetted, for commercial purposes; it is relatively soft; and it is readily workable in knitting and weaving machines.

My inventive-concept may, therefore, be

defined as a spun rayon textile element including cellulose only, In other words, by

Application filed August 11, 1926. Serial No. 128,702.

subjecting rayon and the like to a spinning operation, I am enabled to produce a unique product which marks a distinct advance inthe art, as demonstrated by practical tests and observations.

Usually, rayon, etc., comes to the trade in relatlvely long, untwisted filaments or strands and of various diametralsizes and characteristics; and it is usual practice to run these strands through knitting and weaving machines in the condition they are in when they come from their manufacturer: It is a feature of my concept to treat these strands in a manner that change certain of their characteristics whereby they are greatly improved and rendered more adaptable in the knitting and weaving operations and more serviceable in use. In the first place, these strands or threads (as I shall hereinafter call them for convenience), preferably while dry, are cut into relatively short lengths. In other words, they are subjected to an opera: tion whereby they are reduced to lengths, say, of one and one-half inches. If these elements, so out, are in readily separable and clean condition, they are subjected, succes sively, to the ste s of picking and carding to condition them or spinning, all as more particularly explained in my companion application Serial No. 128,703, filed August 11, 1926, and entitled Method of producingspun rayon elements.

It will be understood,-therefore, thatthe -mass of threads furnished by rayon manufacturers is, under my concept, cut into predetermined short lengths and, then, spun to efiect an interlacing of their component parts whereby an element or yarn results which possesses, to a'recongnizable degree, tensile strength and softness that improve its qualities and properties for fabric purposes. In other words, the resultant product of my method of spinning together cut rayon filament shows, when wot, a far less loss of tensile strength than the original filament-when wetted. The compounding of the cut filament sections does not, of course, lend any greater wet-strength to the individual filaments, but it does make the element comthe spun element develops is probably due to breaking ofthe long filaments of commerce into short lengths so that, when these fibers are brought into combinative association by spinning, the resultant element will possess greater relative flexibility and will likewise possess greater softness.

It is to be understood that rayon, or artificial silk, as produced by its manufacturers, comprises a predetermined number of filaments combined to constitute a strand or thread of a certain number of deniers. For instance, the customary sized rayon filament used in knitting hosiery and underwear is 150 deniers, which-means that a thread of 150 deniers would be composed of twentyfive six-denier filaments. These filaments'are not twisted or spun together in any technical sense.

The des'ideratum, under my concept, is so to combine the small-dimensionedfilaments, pre-cut to relatively short lengths, that they shall, in the ultimate product, have their components combinatively. associated. This is effected by the spinning .operation.

' I am aware. of the fact that it. has heretofore been proposed to cut artificial filaments into relatively long lengthsfour inches or moreand combine them under the so-called worsted or scha e s innin processes. The thread resulting from these practices, however, is quite different in structure from the element produced by the procedure followed by me and wherein there is an intimate combination effected between the several filaments by imparting to theelement a substantial twist.

I am also aware of the fact that it has heretofore been proposed to cut artificial filaments into spinnable lengths and then, following an intermediate operation, spin the same. But my inventive-concept is distinguishable therefrom in that, in that instance,

cotton is mixed with the artificial filament and, then, this mass is subjected to the action of a lapper-machine, after which the cotton is combed out. The combin have found in practice, is etrimental to satisfactory spinning; and, besides, the introduction of the cotton to and its removal from the mass of cut filaments involves an expensive and unnecessary operation.v The resultant of my procedure is an uncombed spun rayon textile element, unaffected byhavoperation, I-

ing been associated with any other fiber during the operation of making it spinnable.

As the result of experiments and tests, it has been found that, by cutting the fine rayon filaments in lengths of approximately one and a quarter to two inches, and spinning these together, as already explained, the new type of textile element is produced, with all of the desirable characteristics of the original filament retained, and with certain additional and desirable characteristics developed therein.

Where I have herein used the term relatively short lengths and similar expressions, it is to be understood that I mean these to comprehend and embrace sections from one and a quarter to two inches, approximately." Experiments indicate that lengths less than one and a quarter inches do not permit of the necessary interlacing of the individual fibers to provide the required strength of the element. On the other hand, sections of substantially greater length than two inches do not work well in the different operations utilized to produce my product.

Where I have herein used the expression wet strength or equivalent terms, I mean thereby the strength of the mass ,when saturated or substantially moistened.

It is to be understood that any loss of luster resulting to the product from the cutting and spinning operations referred to is not detrimental; but, if it be desirable to restore such luster, any appropriate loss-producing operation may be employe It has been discovered that the element may be subjected to moistening and stretching (as effected in accordance with the procedure outlined in the companion application of W. M. Sternberg, filed August 27, 1926, Serial No. 131,966) for this purpose.

In using the expressions soft, softness and like words, I refer to the condition imparted to the product by the steps recited, and which terms, necessarily relative, imply that such product has that characteristic.as compared with the original commercial rayon filament.

Where I have herein employed the expressions rayon, artificial silk and similar terms, it is to be understood that they-and equivalent designations for the material employed'in connection with my invention, shall comprehend and include any thread, threadformation, filament or fiber, in the nature of a more or less lustrous textile element converted from cellulose (whetherit be obtained from wood, cotton or any other vegetable material) by means of chemical and mechanical processes, and whether such basic mass be known as cellulose or viscose.

Where, in the claims, I ,refer to a rayonelement, I mean to designate the commercial product of rayon manufacturers as used by the knitter or Weaver, which element is regulll lli

filaments arranged in substantial parallelism to provide a thread or yarn-forming group.

ere I have herein used the terms spinning, spun, etc., as involving essential steps in my procedure, I wish it to be understood that these terms comprehend that type of textile-yarn manufacturing process which embodies, as its essence, the appreciable and substantial drawing and twisting of the original sliver of material into the finished yarn or thread. These terms are not intended. to include so-called schappe spin-r hing.

What I claim is: l. A rayon textile element comprising a multiplicity of relatively short cellulose filarnent sections of substantially equal length till tit

till

tit

spun together without other material,

9:. A rayon textile element comprising solely a -multiplicity of relatively shortlength uncombed filaments of cellulose spun directly togetherz.

3. A rayon textile element comprising a multiplicity of relatively short uncornbed tilarnent sections composed solel ol cellulose, said filament sections being or substantially uniform length and spun together without other material,

ln testimony whereof, I affix my signature,

ROBERT G. CAMPBELL,

larly composed of a plurality of fine rayon A 

